<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Document</title>
</head>

<body>
  <script>
    class Fa {
      say() {
        console.log('我是爸爸')
      }
    }
    class Son extends Fa {
      say() {
        super.say()
      }
    }

    var ts1 = new Son()
    ts1.say()
  </script>
</body>

</html>